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path: root/drivers/char/watchdog/mpc8xx_wdt.c
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Diffstat (limited to 'drivers/char/watchdog/mpc8xx_wdt.c')
-rw-r--r--drivers/char/watchdog/mpc8xx_wdt.c164
1 files changed, 164 insertions, 0 deletions
diff --git a/drivers/char/watchdog/mpc8xx_wdt.c b/drivers/char/watchdog/mpc8xx_wdt.c
new file mode 100644
index 00000000000..56d62ba7c6c
--- /dev/null
+++ b/drivers/char/watchdog/mpc8xx_wdt.c
@@ -0,0 +1,164 @@
+/*
+ * mpc8xx_wdt.c - MPC8xx watchdog userspace interface
+ *
+ * Author: Florian Schirmer <jolt@tuxbox.org>
+ *
+ * 2002 (c) Florian Schirmer <jolt@tuxbox.org> This file is licensed under
+ * the terms of the GNU General Public License version 2. This program
+ * is licensed "as is" without any warranty of any kind, whether express
+ * or implied.
+ */
+
+#include <linux/config.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/watchdog.h>
+#include <asm/8xx_immap.h>
+#include <asm/uaccess.h>
+#include <syslib/m8xx_wdt.h>
+
+static unsigned long wdt_opened;
+static int wdt_status;
+
+static void mpc8xx_wdt_handler_disable(void)
+{
+ volatile immap_t *imap = (volatile immap_t *)IMAP_ADDR;
+
+ imap->im_sit.sit_piscr &= ~(PISCR_PIE | PISCR_PTE);
+
+ printk(KERN_NOTICE "mpc8xx_wdt: keep-alive handler deactivated\n");
+}
+
+static void mpc8xx_wdt_handler_enable(void)
+{
+ volatile immap_t *imap = (volatile immap_t *)IMAP_ADDR;
+
+ imap->im_sit.sit_piscr |= PISCR_PIE | PISCR_PTE;
+
+ printk(KERN_NOTICE "mpc8xx_wdt: keep-alive handler activated\n");
+}
+
+static int mpc8xx_wdt_open(struct inode *inode, struct file *file)
+{
+ if (test_and_set_bit(0, &wdt_opened))
+ return -EBUSY;
+
+ m8xx_wdt_reset();
+ mpc8xx_wdt_handler_disable();
+
+ return 0;
+}
+
+static int mpc8xx_wdt_release(struct inode *inode, struct file *file)
+{
+ m8xx_wdt_reset();
+
+#if !defined(CONFIG_WATCHDOG_NOWAYOUT)
+ mpc8xx_wdt_handler_enable();
+#endif
+
+ clear_bit(0, &wdt_opened);
+
+ return 0;
+}
+
+static ssize_t mpc8xx_wdt_write(struct file *file, const char *data, size_t len,
+ loff_t * ppos)
+{
+ if (ppos != &file->f_pos)
+ return -ESPIPE;
+
+ if (len)
+ m8xx_wdt_reset();
+
+ return len;
+}
+
+static int mpc8xx_wdt_ioctl(struct inode *inode, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ int timeout;
+ static struct watchdog_info info = {
+ .options = WDIOF_KEEPALIVEPING,
+ .firmware_version = 0,
+ .identity = "MPC8xx watchdog",
+ };
+
+ switch (cmd) {
+ case WDIOC_GETSUPPORT:
+ if (copy_to_user((void *)arg, &info, sizeof(info)))
+ return -EFAULT;
+ break;
+
+ case WDIOC_GETSTATUS:
+ case WDIOC_GETBOOTSTATUS:
+ if (put_user(wdt_status, (int *)arg))
+ return -EFAULT;
+ wdt_status &= ~WDIOF_KEEPALIVEPING;
+ break;
+
+ case WDIOC_GETTEMP:
+ return -EOPNOTSUPP;
+
+ case WDIOC_SETOPTIONS:
+ return -EOPNOTSUPP;
+
+ case WDIOC_KEEPALIVE:
+ m8xx_wdt_reset();
+ wdt_status |= WDIOF_KEEPALIVEPING;
+ break;
+
+ case WDIOC_SETTIMEOUT:
+ return -EOPNOTSUPP;
+
+ case WDIOC_GETTIMEOUT:
+ timeout = m8xx_wdt_get_timeout();
+ if (put_user(timeout, (int *)arg))
+ return -EFAULT;
+ break;
+
+ default:
+ return -ENOIOCTLCMD;
+ }
+
+ return 0;
+}
+
+static struct file_operations mpc8xx_wdt_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .write = mpc8xx_wdt_write,
+ .ioctl = mpc8xx_wdt_ioctl,
+ .open = mpc8xx_wdt_open,
+ .release = mpc8xx_wdt_release,
+};
+
+static struct miscdevice mpc8xx_wdt_miscdev = {
+ .minor = WATCHDOG_MINOR,
+ .name = "watchdog",
+ .fops = &mpc8xx_wdt_fops,
+};
+
+static int __init mpc8xx_wdt_init(void)
+{
+ return misc_register(&mpc8xx_wdt_miscdev);
+}
+
+static void __exit mpc8xx_wdt_exit(void)
+{
+ misc_deregister(&mpc8xx_wdt_miscdev);
+
+ m8xx_wdt_reset();
+ mpc8xx_wdt_handler_enable();
+}
+
+module_init(mpc8xx_wdt_init);
+module_exit(mpc8xx_wdt_exit);
+
+MODULE_AUTHOR("Florian Schirmer <jolt@tuxbox.org>");
+MODULE_DESCRIPTION("MPC8xx watchdog driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);